US official: We have evidence Russia is firing missiles into Ukraine

View full sizeUkrainian Prime Minister Arseniy Yatsenyuk speaks in the parliament in Kiev, Ukraine, Thursday, July 24, 2014. Arseniy Yatsenyuk announced his resignation Thursday, a move that opens the way for new elections that would reflect a the countryâs starkly changed political scene after the ouster of pro-Russian President Viktor Yanukovych in February. (AP Photo/Andrew Kravchenko, Pool)

A spokeswoman for the State Department said the United States has proof that Russia is firing missiles into Ukraine.

According to an Associated Press story, U.S. defense and diplomatic officials have confirmed that Russia is shooting at Ukrainian military positions, but would not give details on the intelligence that had been gathered.

According to the story, a spokesman for the Russian embassy in Washington disputed the allegations.

"Unfortunately, it is not for the first time that we hear unproven allegations," the spokesman said. "In fact, it is the Russian territory that is being shelled from the Ukraine."

CNN reported that U.S. officials believe Russia is planning to give a heavier rocket launcher to separatists to be used in their fight against the Ukrainian military.

"We have new evidence that the Russians intend to deliver heavier and more powerful multiple rocket launchers to the separatist forces in Ukraine and have evidence that Russia is firing artillery from within Russia to attack Ukrainian military positions," State Department spokeswoman Marie Harf said.

More than 400 people have died in the fighting between the separatists and the Ukrainian government.

Meanwhile on Thursday, Ukrainian prime minister Arseniy Yatsenyuk announced that he would be resigning after the collapse of his coalition.